Printer



Jan. 26, 1960 c. E ADLER EIAL 2,922,361

PRINTER 15 Sheets-Sheet j.-

Filed Nov. 1, 1957 INVENTORS. CLARENCE E. ADLER I GEOFFREY T. GRAYATTORNEXS 5 Jan. 26, 1960 c. E. ADLER ETAL 2,922,361

PRINTER Filed Nov. 1, 1957 15 Sheets-Sheet 2 INVENTORS.

CLARENCE E. ADLER G EOFFREY T. GRAY BY ATTORNEYS Jan. 26, 1960' c. E.ADLER ETAL 2,922,361

PRINTER 15 Sheets-Sheet 3 Filed Nov. 1. 1957 INVENTORS CLARENCE E.ADLERGEOFFREY I GRAY ATTNEYS Jan. 26, 1960 c; E. ADLER ETAL PRINTER FiledNov. 1. 1957 15 Sheets-Shet 4 INVENTORS. CLARENCE E.ADLER GEOFFREY T.GRAY ATTORNEYS Jan. 26, 1960 c, ADLER ETAL 2,922,361

PRINTER 15 Sheets-Sheet 5 Filed Nov. 1. 1957 INVENTORS. CLARENCE E.ADLERG EOFFREY T. GRAY lMW Jan. 26, 1960 c. E. ADLER ET AL 2,922,361

PRINTER l5 Sheets-Sheet 6 Filed Nov. 1, 1957 i uzlzz:

INVENTORS. CLARENCE E.ADLER GEOFFREY T. GRAY BY 2g; ATTORNEYS PRINTER l5Sheets-Sheet 7 Filed Nov. 1. 1957 0 I 2 8 l ole '70 i $1 a 4 W L B 7. 8

'INVENTORS. CLARENCE E. ADLER Jan. 26, 1960 c. ADLER ETAL Y 2,922,361

PRINTER Filed Nov. 1, 1957 15 Sheets-Sheet 8 INVENTORS- CLARENCE E.ADLERGEOFFREY T. GRAY BY E a/zggz gi'i ATTORNEY Jan. 26, 1960 c. E, ADLEREIAL 2,922,361

PRINTER l5 Sheets-Sheet 9 Filed Nov. 1, 1957 1 mans CLAREN 5E. ADLERGEOFFREY T. GRAY ATTORNEYS Jan. 26, 1960' c, E, ADLER ETAL 2,922,361

PRINTER Filed NOV. 1. 1957 15 Sheets-Sheet 11 INVENTORS. CLARENCEE.ADLER GEOFFREY T GRAY ATTOR NEYS Jan. 26, 1960 c. E. ADLER ETALPRINTER 15 Sheets-Sheet 12 Filed Nov. 1. 1957 INVENTORS. CLARENCE E.ADLER GEOFFREY T. GRAY ATTORNEYS Jan. 26, 1960 c. E. ADLER ETAL2,922,361

PRINTER Filed Nov. 1, 1957 15 Sheets-Sheet 1s INVENTORS. 0 m CLARENCEE.ADLER I19. GEOFFREY T GRAY ATTORNEYS Jan. 26, 1960' c. s, ADLER EIAL2,922,361

PRINTER 15 Sheets-Sheet 14 Filed Nov. 1. 1957 INVENTORS. CLARENCE E.ADLER GEOFFREY T.GRAY

' -ATTORNEYS (\l cu Jan. 26, 1960 c. E. ADLER ET AL 2,922,361

PRINTER 15 Sheets-Sheet 15 CLARENCE E. ADLER GEOFFREY T GRAY BYATTORNEYS Filed NOV. 1, 1957 United State PRINTER Clarence E. Adler andGeoffrey '1. Gray, Toledo, Ohio,

assignors, by mesne assignments, to Toledo Scale (101'- poration,Toledo, Ohio, a corporation of Ohio Application November 1, 1957, SerialNo. 693,975

12 Claims. (Cl. 101-95) This invention relates to an improved printingdevice.

Printing devices often include type positioning mechanism for aligning aplurality of printing members, such as type wheels or sectors, eachhaving a series of printing type and a series of locating notchespositioned with respect to the raised printing type. The typepositioning mechanism often includes a driven member upon which ismounted a centering bar that is used to align the locating notchesfinally after the printing members have been selectively positionedapproximately. Heretofore, such type positioning mechanism generally hasbeen unsatisfactory because the centering bar fitted closely in thelocating notches and when the notches were of different sizes and depthsand/ or the axes of rotation of the printing members and the drivenmember were not parallel, as may occur in mass production manufacturing,it was impossible for a single centering bar to align the printingmembers accurately so that they would print in a straight line. That is,a single centering bar which fits closely in such locating notchescannot perfectly align the notches unless the bottoms of a row ofequally sized notches extend in a straight line that is parallel to thecentering bar.

After the type positioning mechanism has positioned the printing membersfinally and while such members are locked in their final positions bythe type positioning mechanism, a roller printer often is used to pressan element to be printed, such as a ticket, against the printing type onthe printing members. Heretofore, many roller printers have been drivenboth on a forward printing stroke and on a return stroke for eachprinting operation, which often caused double impressions of theprinting type, and, in order to accommodate elements to be printed ofdifferent thicknesses, it has been necessary selectively to adjust thepressure with which the roller printers pressed the elements against theprinting type. Attempts to eliminate such double impressions and toprovide means for making such adjustments have resulted in expensive andcomplicated roller printers.

It is, accordingly, the principal object of this invention to provide animproved printer that is of simple and low cost construction, yet isrugged, reliable and accurate, and which produces well aligned printedmatter, is easy to maintain, and is adaptable to many different printingapplications.

Another object of the invention is to provide a printing device havingimproved type positioning mechanism for finally aligning and lockingprinting members after such members have been selectively positionedapproximately in combination with an improved roller printer which,while the printing members are locked in their finally alignedpositions, presses an element to be printed against the printingmembers.

Still another object of the invention is to provide type positioningmechanism which cooperates with locating slots or notches in a pluralityof printing members and which is able to accurately align the printingmembers even though such locating slots or notches are of differentwidths and/or depths as may occur in mass production manufacturing.

A further object is the provision of a roller printer which is adaptedto press an element to be printed against printing members on a forwardprinting stroke during one 2,922,351 Patented Jan. 26, 1960 printingoperation and to press another element to be printed against theprinting members on a return printing stroke during another printingoperation to eliminate the occurrences of double impressions and toenable the roller printer to be made of simplified construction.

A still further object is the provision of a roller printer which isautomatically adjustable to accommodate elements to be printed ofdifferent thicknesses.

Other objects and advantages will be apparent from the followingdescription in which reference is had to the accompanying drawings.

A preferred form of the improved printer is illustrated in theaccompanying drawings.

In the drawings:

Figure I is an elevational view of a weighing scale dial mechanismshowing the location of the improved printer as it is mounted on aweighing scale;

Figure II is a fragmentary schematic diagram to illus trate some of theoperating principles of a mechanical chart reading device for use inconnection with the weighing scale that is illustrated in Figure I toread the graduations of the chart shown in Figure I that moves accordingto the weight of a load being weighed and to set up the printer forprinting the weight indications in digital form;

Figure III is a diametric view of the chart reading device showing astack of permutation members and the drive mechanism therefor to showtheir cooperation with each other and with the weighing scale chart;

Figure IV is a horizontal section through the lower portion of theassembly of. permutation members which is illustrated in Figure III toshow the cooperation between the permutation members and the drivetherefor;

Figure V is a plan view of one of the permutation membersto show itsnotch pattern;

Figure VI is a fragmentary plan viewof the notched portion of anotherpermutation member to show a second notch pattern;

Figure VII is a front elevational view of the weighing scale chart whichis mechanically sensed axially by the permutation chart reading device;

Figure VIII is an enlarged fragment of the graduated portion of theweighing scale chart which is illustrated in Figure VII;

Figure IX is a section at enlarged scale taken substantially along theline IXIX of Figure VIII to illustrate the shape of the individual chartgraduations;

Figure X is a section at enlarged scale taken substantially along theline XX of Figure VIII to show the shape of locating notches employed tolocate the chart prior to taking a reading;

Figure XI is a table showing the permutation code used for each of thegraduations of the weighing scale chart;

Figure XII is an exploded view of locating mechanism employed to centerthe chart graduations prior to taking a reading so as to avoid anypossibility of selector pins of the permutation members failing toproperly engage the chart graduations;

Figure XIII is a plan view of the locating device;

Figure XIV is a vertical section along the line XIV XIV of Figure XIII;

Figure XV is a perspective view of the printer with part of its caseremoved to reveal the printing mechanlsm;

Figure XVI is a perspective View from another angle of the printer;

Figure XVII is an enlarged elevational view of the end of the printerwhich may be seen in Figure XVI;

Figure XVIH is a horizontal sectional view taken along the lineXVIII-XVIII of Figure XVII;

Figure XIX is a vertical sectional view taken along the line XIX-XIX ofFigure XVII;

v v V 3 Figure XX is an enlarged end elevational view of the printer asseen from a position at the left of Figure XV looking toward theprinter;

Figure XXI is an enlarged, fragmentary front elevational view as seenfrom a position in front of Figure I looking toward the printer, thecase being removed to reveal the inner mechanism;

Figure XXII is an end elevational view of one of the printing sectorsand its cable drive which are illustrated in Figure XXI;

Figure XXIII is a plan view of the cable guide shaft which is shown inFigure XXII;

Figure XXIV is an enlarged sectional view taken along I the lineXXIVXXIV of Figure XXIII;

Figure XXV is an enlarged, fragmentary, detailed and more or lessschematic view of the printing sector which is illustrated in FigureXXII;

Figure XXVI is an enlarged, fragmentary front elevational view as seenfrom a position in front of Figure I at a position to the left of FigureXXI looking toward the printer, the printer case being removed and theprinter housing being sectioned and broken away to reveal the innermechanism;

Figure XXVII is an elevational view as seen from a positionsubstantially along the line XXVII-XXVII of Figure XXVI looking in thedirection indicated by the arrows;

Figure XXVIII is a plan view of the mechanism which is illustrated inFigure XXVII;

Figure XXIX is a reduced, vertical sectional view of the roller printermechanism within that part of the printer housing which is shown brokenaway at the right printer with the printing sectors which are locatedabovethe roller printer;

Figure XXX is an enlarged elevational view of the roller mechanism whichis shown in Figure XXIX;

Figure XXXI is a plan view of the mechanism which is shown in FigureXXX; and

Figure XXXII is a perspective view of the printing roller and itsresilient mounting.

These specific figures and the accompanying description are intendedmerely to illustrate the invention and not to limit its scope.

For the purpose of illustration, the improved printer is shown inconnection with a mechanical chart reading device that is described inconnection with its use in an ordinary dial type weighing scale forreading the graduations of a chart that moves according to the weight ofa load being weighed and for setting up the printer for printing weightindications in digital form. It is to be understood that the printer maybe operated by any of the usual means for setting up printing members,such as type wheels or sections, or by hand and that it is shown inconnection with the mechanical chart reading device for illustrativepurposes only. Such a weighing scale comprises a dial housing 1 thatcontains automatic load counterbalancing and indicating mechanism whichmay include a chart 2 that is rotated through increments of angle thatare proportional to increments of weight applied to the scale. The charthousing 1 is mounted on the top of a scale column 3 of which only thetop portion is shown in Figure I.

The mechanical chart readingmechanism is located within the dial housing1 and is connected to the improved printerwhich is contained within itshousing 5 and case 6 and operated according to the scale readings. Thechart 2 has on its face a series of graduations 7 that are visiblethrough a magnifying lens 8 to provide visual indications ofthe load onthe scale. The face of the chart 2 is also provided with moldedgraduations or indicia 9 consisting of relatively raised and depressedsurfaces, as shown in greater detail in Figures VIII, IX and X,contstituting the indicia that are sensed by the reading device.

- of Figure XXVI showing the cooperation of the roller Figure H shows inschematic form one of each of the essential elements of the readingdevice while Figure III shows a complete assembly of the sensing andselecting portions of the reading device. Referring first to Figure II,a reading of the chart 2 is taken by first advancing a series of sensingpins 10, one of which is shown, by springurged rotation of permutationdisks 11 to positions at which they are arrested by engagement of thesensing pins 10 with the indicia 9 of the chart 2. Prior to theengagement of the sensing pins 10 with the indicia 9, a cam 12 formingpart of a drive member 13, through engagement with a roller 14, drives aresiliently mounted finger 15 toward the chart until its tip 16 engagesa row of raised teeth 17 and comes to rest either between adjacent teethor on the crest of a tooth. Continued motion of the cam follower 14turns a rubber tired wheel 18 in a direction tending to move the chart 2so that the tip of the finger 16, if it had lodged on a crestof a tooth17, is permitted to enter the space between two of the teeth and thuslocate the chart 2. If the tip 16 were already engaged in a spacebetween two of the teeth 17, the wheel slips leaving the chart 2 inposition with the corresponding graduation centered in the path of thesensing pins 10. Thus, the pins 10 either enter squarely into the spacesbetween indicia 9 or onto the crests depending upon the coding of theindicia for that particular graduation.

After the permutation disks 11 are retracted, without disturbing theirrelative positions as determined by the engagement of the sensing pins10 with the chart 2, search pawls 20, one for each decade, carried onpawl carriers 21 and each cooperating with four of the permutation disks11 search notches 22 in the peripheries of the permutation disks 11. Aseach pawl finds aligned notches in its set of four permutation disks 11it stops its associated pawl carrier in a position corresponding to theparticular graduation of the chart being sensed. The stopped pawlcarriers, through their connections through cables 23, position printingsectors in the printer according to the sensed graduation.

The movement of the drive member 13 is produced and controlled by aconnecting rod 24 and crank 25 driven by a motor 26 equipped withcontrols to cause it to drive the crank 25 through one revolution foreach start signal.

The sequence of steps in thus taking a reading from the chart 2 is toenergize the motor such that it turns the crank 25 and thus oscillatesthe drive member 13. This oscillation first drives the cam follower 14and finger 15 toward the chart to locate it with a graduation accuratelyin line with the sensing pins 10. During the oscillation of the drivemember 13 the permutation disks 11, four for each decade, are driven sothat their respective pins 10 engage the chart and then are retractedwithout disturbing their relative positions with respect to each otherto a locking position at which they are held while the searching pawls20, one for each group of four permutation disks or one for each decade,search the peripheries of the permutation disks 11 for the alignednotches. Upon finding the aligned notchesthe pawls stop the respectivepawl carriers 21 in proper indicating positions.

The whole combination or assembly of permutation disks and drive membersis shown in greater detail in Figure III. The complete stack up ofpermutation disks 11 for a four place number includes sixteen of thepermutation disks 11, four pawl carriers 21, and enough spacers 27 toseparate each of the permutation disks 11 from its neighbor or from apawl carrier 21 as the case may be. Thus, sixteen permutation disks 11and four pawl carriers 21 plus an extra spacer at the top of the stackrequires a total of twenty-one spacers 27. Each of the spacers isprovided with a pair of bifurcated cars 28 and 29 adapted to slip intonotches in support rods of a frame with the rods holding the spacers inalignment and in spaced relation. Each of the spacers, on the sidefacing the chart, also has an inwardly directed notch 30 that terminatesin a narrow slot 31 adapted to fit into a corresponding groove cut in anaxle 32 on which the permutation disks 11 and pawl carriers 21 arejournaled. Thus, each of the spacers 27 has a three point support so asto separate the permutation disks and still allow them to move easily asmay be required in sensing the chart or in carrying the pawls 20 alongthe notched peripheries of the permutation disks 11.

The sensing pins each has a pointed end 33 that is 'sharp enough toenter the spaces between alternate graduations and yet blunt enough toavoid cutting the chart material and has its other end curled into acircular loop 34 that is a close sliding fit in a hole cut in theconnected permutation disk 11 so that the pin moves in the manner of aflat ball and socket joint. This particular construction keeps thethickness of the permutation disk and pin a minimum so that it may fitbetween closely spaced adjacent spacers 27.

The permutation disks 11 are continually urged in a direction tending todrive the sensing pins 10 against the chart by spring teeth 35 of a combspring 36 that is carried on a common pawl bail 37. The ends of thespring teeth 35 engage notches 38 in the permutation disks. Movement ofthe permutation disks 11 under the influence of the springs 35 islimited by a common pawl 40 that is carried in the bail 37 and arrangedto selectively engage either of two notches 41 or 42 of each permutationdisk 11 and lock it in position when the pawl engages hook-like portions43 (Figure IV) of the bifurcated ears 29 as the bail 37 is urgedcounterclockwise, as seen in Figures 111 and IV, by a return spring 44attached to its lower end. The common pawl 40 is held seated in pivotnotches 45 of the bail 37 by a plurality of small springs 46 formingpart of the comb spring 36 and attached to the bail 37. The pawl 40 isurged into engagement with the notches 41 or 42 by a light spring 47also attached to the bail 37.

In operation, as the drive member 13 is swept clockwise as seen inFigure III or IV it collects the pawl carriers 21 from their previouspositions and finally engages an upwardly directed stud 48 carried in anupper arm 49 of the bail 37 so as to drive the bail clockwise through asmall distance against the tension of the return spring 44. During theinitial movement of the bail 37 it and the permutation disks 11 move asa unit since the disks are held between the spring teeth 35 engaging thenotches 38 and the pawl 40 engaging the notches 41 or 42. As the sensingpins 10 engage the chart 2 and drive it agm'nst a backup roller 50 themotion of the permutation disks 11 is arrested. The spring teeth 35yield as the bail 37 continues and the pawl 40 leaves the notches 41 or42 and slides part way along the smooth periphery of the permutationdisks 11 between the notches 41 and 38. This motion is just enough tomake sure that the common pawl 40 is out of the notches. ber 13, thespring 44 pulls the common pawl bail 37 counterclockwise so that thecommon pawl 40 may enter the aligned ones of the notches 41 or 42 ineach of the permutation disks according to whether the disk had beenadvanced by its pin finding a low spot in the chart or whether it hadbeen arrested in the first position with the pin on the crest of agraduation. The continued motion with the common pawl 40 engaged in thepermuta tion disks drives the disks in retracting motion until thecommon pawl 40 seats behind the hook-like portions 43 of the spacer ears29. At this point the motion of the common pawl bail 37 is arrested andthe permutation disks 11 are all locked in position.

Continuing motion of the drive member 13 allows the pawl carriers 21 tofollow as urged by their drive springs 52, one of which is shown inFigure IV connected to its cable 23. The pawl carriers 21 move untiltheir pawls find aligned notches in a particular combination ofpermutation disks with which they cooperate. It is to be noted that theposition of the aligned notches may vary On the return motion of thedrive mem according to the relative positions of the group of diskscooperating with each pawl.

The sensing pins 10 adjacent the chart 2 are guided in slots 54 of aguide plate 55 that is attached to a frame support 56 that serves as thespacing support for the bifurcated ears 28 of the spacers 27. The slots54 are just wide enough to admit the pins and, thus, accurately guidethem closely adjacent the chart 2. As indicated in Figure IV, the guideplate 55 is adjustable relative to the frame support rod 56 and iscontrolled by an adjusting screw 57 that works in opposition to thecommon pawl bail return spring 44.

The return springs 52 are located in the printer, as hereinafterdescribed, and maintain tension on the cables 23 which are run from theselector mechanism into the case 6.

Referring to Figure IV, each cable 23 is passed over an arcuate surfaceor periphery 58 of its pawl carrier 21 and its end is anchored in a hole59 drilled through the pawl carrier. The spacers 27 hold the cable 23from slipping off sideways. The radius of the arcuate surface 58 withrespect to the axle 32 on which the pawl carrier is journaled isselected according to the desired travel of the cable 23 for eachincrement of indication and the spacing of the notches 22 whichdetermine the angular travel of the pawl carrier.

The permutation disks 11 are made with either of two notch patterns andthe selector pawls 20 are arrangedwith one of its teeth advanced twonotch spaces ahead of the other tooth. By thus varying the spacing ofthe pawl teeth and providing the two different patterns for the selectordisks it is possible to secure at least eleven different combinations toprovide different stopping points for the pawl 20. Figures V and VI showthe two notch combinations for the permutation disks 11. In the typeshown in Figure V the notched periphery is divided into twenty-threeequal spaces with notches appearing in the first, third, fourth, sixth,ninth, tenth, twelfth, fifteenth, seventeenth, eighteenth, twentieth,and twenty-third spaces counting from left to right. Likewise, thepermutation pattern shown in Figure VI has notches appearing in thefirst, second, fifth, sixth, ninth, tenth, thirteenth, fourteenth,seventeenth, nineteenth, twenty-first, and twentythird spaces. Theseparticular notch combinations used in pairs with the offset pawl teethoperate according to the code set forth in Figure XI. This code is usedin determining the location of the raised indicia for each of thegraduations on the chart 2 to be sensed.

As shown in Figure VII, the chart 2 is an annular member carried on aspider 6t) and having rows of graduations 61 on its marginal area. Inorder to allow for expansion and contraction of the chart 2 and thespider 60 relative to each other due to temperature changes, the spider60 is slotted radially at 60a to loosely receive a rivet 61a, hasopenings 60b which loosely receive rivets 61b, and has an aperture 60cwhich fits snugly about rivet 610. The rivets hold the chart 2 and thespider 60 together, the heads of the rivets being sheared off and thebodies of the rivets shown in section in Figure VII for clarity ofillustration. The graduations or indicia are preferably molded in theface of the chart in the same manner as phonograph records are made witha plastic or other moldable layer 62 mounted on a metallic backing plate63 and the graduations being formed in the plastic layer. Thearrangement of graduations for a first fragment of the chart isillustrated in Figure VIII. This fragment, starting with the zeroindicia of the chart, shows only those graduations in the units orlowest order decade and the row of teeth 17 for locating the chart. Theteeth 17 along the marginal area of the chart cooperate with thelocating finger 15 and have cross sections as shown in Figure X whereineach of the teeth is shown substantially as a conventional rack tooth.The tip 16 of the locating finger 15 is formed as a mating tooth so asto seat firmly in the spaces between the teeth 17.

The indicia 9 with which the sensing pins 10 cooperate are of generallysimilar shape except for being formed of heavier section inasmuch as thelocating pins do not have to fit into the spaces between teeth that arelocated on adjacent graduations. The chart section shown in Figure VIII,as was mentioned, includes that portion starting at the zero graduationwhich is shown at the right-hand edge. Inasmuch as there are nosignificant figures to the left of the zero when indicating the zerograduation it is desirable that the printer print a blank at thisposition. Therefore, the first graduation carries only the single raisedportion in the bottom row or D row which, according to the chart shownin Figure XI, gives a blank for the output indication. The permutationdisk combination for this graduation causes the aligned notch to appearat the end of the travel of the pawls 20 or at the last possibleposition at which an aligned notch may be formed. If an error is madesuch that the pawl does not find the aligned notch it over travels andthe printer indicates such overtravel by printing some distinctivesymbol, such as an E, in place of a digit. The next graduation, a one,is indicated or denoted by a single raised indicia in the A row;likewise two is indicated by a single indicia in the C row; and theothers follow according to the chart. It should be noted that the raisedindicia of the chart cause the corresponding permutation disk 11 to beadvanced counterclockwise one space as seen in Figure III or IV.

Other chart combinations may be employed besides the particular codeindicated. However, this particular code was selected in order that thenumber of different parts could be reduced. Thus, with the selected codetwo each of the permutation disks 11, shown in Figures V and VI, may beemployed in each decade in combination with the offset pawl 20. If theoffset pawl were not employed then each of the four permutation diskscooperating for each decade would have to have its own combination ofnotches which would make four different parts to be stocked instead oftwo.

The plastic layer 62 is firmly attached to the metallic backing plate 63either by molding it in place or by adhesively applying it. The plasticlayer is then impressed in a molding operation with the rows ofgraduations 61. The metallic backing plate 63 has appreciable thicknessand the moldable material 62 applied to its surface is of substantiallythe same thickness. The moldable material must be thick enough to takethe full depth of the impressions to be molded therein without havingthe dies of molds extend through to the metallic supporting member.

Preferably, the plastic layer 62 is molded into form and applied to thebacking plate 63 in one operation. Since heavy, rigid molds are requiredto mold the plastic layer these may be very accurately made so that themolded graduations 61 are precisely located around the chart and so thatthey are sharply formed, whereby the graduations are especially suitablefor accurate sensing by the feeler pins 10.

The composite chart 2 is preferably constructed from hard aluminum alloyso that it is dimensionally stable and able to stand the pressures inthe mold. The moldable material may be a soft metal alloy or any of theplastics which will adhesively bond to the aluminum. Ordinarily, athermoplastic material is employed so that the graduations will be veryaccurately molded by the application of heat and pressure. Thermoplasticmaterials are preferred although thermosetting materials may also beused provided that they will adhere to the aluminum or other metal usedfor the stable support. Suitable materials for coating the mold surfaceare available to prevent adhesion of the molded layer of the chart tothe mold.

The foregoing described construction" for the chart 2 permits it to bemade at a small cost and with an accuracy amen Various modifications ofconstruction and substitutions of material in the chart 2 may be madewithout losing the advantages that are obtained by using a highstrengthdimensionally stable material as a backing sheet or support and moldedonto a marginal area thereof a layer of moldable material onlysufficiently thick to receive the impressions of gradnations or indiciato be placed thereon.

The chart locating mechanism is illustrated in greater detail in FiguresXII, XIII and XIV. Referring to Figure XII, the cam follower 14 ismounted on the end of a forearm 65-that also carries, as a rigid partthereof, at its elbow end the drive wheel 18 that engages the chart tourge it forward so as to move any tooth 17 falling below the finger tip16 out of the way and allow the tip 16 of the finger 15 to fall into thespace between adjacent teeth 17. The arm 65 is pivotally connectedthrough an elbow joint at the axis of the wheel 18 to a second arm 66which in turn is pivoted on and, by a spring not shown, is continuallyurged clockwise about a pin 67 fixed in the framework of the scale. Aspring 63 at the joint or elbow at the Wheel 18 urges the forearm 65clockwise with respect to the second arm 66 so that the wheel bearsagainst the chart 2' before the elbow joint starts to turn. The springurged movement of the forearm 65 relative to the second arm 66 islimited by a down turned car 69 on the, tail end of the forearm 65 thatengages the front surface of the lower arm 66. Normally, the spring 68rotates the forearm 65 to maintain the ear in engagement with the lowerarm. However, when the mechanism is pushed toward the chart by the campushing on the cam roller 14 the lateral motion of the wheel 18 isarrested and the cam force against the cam follower 14 then rotates thearm 65 between the arms 65 and 66 and shows a rubber tire 72 mounted onthe wheel 18 so as to increase the tractive effort of the wheel on thechart- In the operation of this mechanism the spring 68 is made stiffenough so that when the wheel 18 engages the chart it pushes the chartback against the backup roller 50 before the spring 68 yields andpermits the arm 65 to turn relative to the arm 66. This insures thatsuflicient force is exerted against the chart to cause it to move eventhough the tip 16 of the finger 15 should be partially caught on thecorner of the crest of a tooth. It is necessary that sufiicient force beexerted at this time so that the tip of the finger 15 will slide acrossthe crest of a tooth 17 and firmly engage in the valley against the sideof the next tooth 17.

Referring to Figures XV and XVI, the cables 23, one for each decade in afour place number, are led through ordinary Bowden cable casings 73 thatare attached by means of adjustment clips 74 to a stationary support 75within the dial housing 1 and that run through an opening 76 in the dialhousing 1 into the printer case 6. The ends of the cables 23, ashereinbefore described in connection with the more or less schematicillustration of one of the return springs 52 shown in Figure IV, areconnected to the return springs 52 that actually are located 9 in theprinter as illustrated in Figures XX and XXI. The printer is driven bymeans of a horizontal shaft 77 which is driven in turn by the motor 26(Figure II), the operative connection between the shaft 77 and the motor26 not being shown; however, it is to be understood that every time themotor 26 drives the crank 25 through one revolution in response to astart signal it also turns the shaft 77 through one revolution. Theshaft 77 extends from the dial housing 1 into the printer case 6 todrive the mechanism therein and also carries a miter gear '78 whichmeshes with a cooperating miter gear 79 that is attached to a verticalshaft 80 (Figure XXVI) which drives that part of the printer mechanism(roller printer) contained within the printer housing 5. Every time thatthe horizontal shaft 77 is turned through one revolution it drives thevertical shaft 80 through one revolution.

The mechanism within the printer case 6 is driven by means of cams 81and 82 (Figures XVII and XVIII) fixed to the shaft 77, the shaft 77being journaled within the dial housing 1 in the support 75 (FigureXVI), within the printer case 6 in a vertical end frame 83 (Figures XVIIand XVIII) and intermediate its ends in a supporting member 84 (FigureXXVI). Horizontal, sleeve-like spacers 85, two of which are shown inFigure XV, space the vertical end frame 83 from the dial housing 1,bolts 86 which extend through openings 87 in the end frame 83 andthrough the sleeve-like spacers 85 functioning to attach the end frameto the dial housing.

The cam 81 functions to reciprocate a cam follower plate 88, asindicated by the double-ended arrow in Figure XVII, that drives an inkedribbon reverse mechanism and a record strip mechanism. The cam followerplate 88 is connected to a slidable bar 89 by means of a togglemechanism 90 which comprises a bracket 91 fixed to the slidable bar 89,an arm 92 pivotally mounted on a bracket 91 by means of a pivot pin 93,and a bowed spring 94 the ends of which engage in opposed V-notches inthe bracket 91 and in the arm 92. An upwardly extending portion of thearm 92 is movable within limits defined by the ends of a notched-outportion 95 (Figure XVIII) of the bar 89, the bar 89 being slidable inthe slotted arms 96 of a bracket 97 which is attached to the end frame83 by means of screws 98. The bracket 97 also functions to support ashoulder screw 99 which cooperates with a horizontal slot 100 in the camfollower plate 88, the reciprocable plate 88 being slidable on theshoulder of the screw 99 and being pivotally attached on the upper endof the arm 92 of the toggle mechanism 90 by means of a pivot pin 101.

The end frame 83 has mounted therefrom a pair of shafts 102 and 103(Figure XVII) on which is fixed a pair of ribbon spools 104 and 105(Figures XV, XVI and XX), respectively. Adapted to be wound and unwoundalternately on the spools 104 and 105 is an inked ribbon 106 which ismoved back and forth through a printing station as indicated by thedouble-ended arrows in Figure XX. Pinned to the shafts 102 and 103,respectively, is a pair of ratchet wheels 107 and 108 the teeth of whichare arranged so that they are driven in opposite directions.Reciprocation of the cam follower plate 88 to the right as viewed inFigure XVII causes a pawl 109 (Figure XVIII) that is carried by an endof the slidable bar 89 and that extends through an opening 110 in theend frame 83 to cooperate with and drive the ratchet wheel 108 whichrotates its spool 105 slightly so as to advance the ribbon 106. Theslidable bar 89 and the toggle mechanism 90 are driven through adefinite prescribed stroke which is less than the total range of travelof the slidable bar 89. When the toggle mechanism 90 is operated, thestroke of the slidable bar 89 is shifted from one end of its range oftravel to the other. With the arm 92 of the toggle mechanism 90 at theleft end of the notched-out portion 95, as shown in Figures XVII andXVIII, the slidable bar 89 and the toggle mechanism 90 are reciprocablein a stroke 10 so that the pawl 109 drives the ratchet wheel 108counterclockwise as viewed in Figure XVII and so that a pawl 111 that iscarried by the other end of the bar 89 and that extends through anopening 112 in the end frame 83 is reciprocable in an area where it doesnot cooperate with and drive itsratchet wheel 107, the spool 104 carriedby the shaft 102 acting as a supply roll for the ribbon 106 as theribbon is Wound upon the spool 105.

The bowed spring 94 acts as a compression link between the bracket 91and thearm 92 of the toggle mechanism. The force exerted by the spring94 tending to keep the arm 92 against one end or the other of thenotched-out portion is slightly greater than the force required to drivethe spool on which the ribbon 106 is being wound. During operation, thespring force can be overcome when the pawl doing the driving can nolonger rot-ate its ratchet wheel, such as when the ribbon 106 tightensas it reaches its end on the supply roll. When the tension in the ribbon106 increases to a certain point because the ribbon has reached its end,the pawl driving the ratchet Wheel of the take-up spool prevents theslidable bar 89 from reciprocating. The reciprocating cam follower plate88 continues to move, however, and in so doing actuates the togglemechanism 90 to shift the stroke of the slidable bar 89 to wind theribbon 106 on what formerly was the supply spool. When the togglemechanism shifts to the right end of the notched-out part 95, as viewed'in Figures XVII and XVIII, to shift the stroke of the slidable bar 89from one end of its range of travel to the other. The slidable bar 89and the toggle mechanism 90 then are reciprocable in a position so thatthe pawl 111 drives the ratchet wheel 107 clockwise as viewed in FigureXVII and so that the pawl 109 is reciprocable in an area where it doesnot cooperate with and drive its ratchet Wheel 108, the spool carried bythe shaft 103 acting as a supply roll for the ribbon 106 as the ribbonis wound upon the spool 104. Hence, the inked ribbon 106 automaticallyis wound and unwound alternately on the spools 104 and 105 by the ribbonreverse mechanism.

Fixed respectively to the ratchet wheels 107 and 108 is a pair ofgrooved hubs 113 and 114 (Figure XX) each of which receives a spring 115which acts as a friction brake. The springs 115 are looped around thehubs 112) and 114 and have their opposite ends stationari-ly attached at116 to the end frame 83. The springs 115 maintain the inked ribbon 106under proper tension to present it to the printing station without toomuch slack and prevent the driven one of the spools 104 and 105 frombacking up during the return stroke of the bar 89.

While the cam follower plate 88 is driving the inked ribbon 106 one wayor the other, the plate 88 also drives the record strip mechanism in thedirection indicated by the single-ended arrows in Figure XX. The recordstrip mechanism includes a pair of shafts 117 and 118 (Figure XVII), apaper supply spool 119 (Figure XX) rotatably journaled on shaft 117 anda paper take-up'spool 120 (Figures XV and XVI) fixed to turn as one withshaft 118, a translucent record strip 121 being drawn from the supplyspool 119 and being wound upon the driven take-up spool 120. A frictionbrake spring 122, which is like the springs 115, cooperates with agrooved hub 123 on the spool 119 and functions to maintain the recordstrip 121 under proper tension.

The driven paper take-up spool 120 is turned by a drive which includesthe reciprocable cam follower plate 88, a rockable plate 124 which ispivotable about the axis of a rotatable shaft 125 (Figure XIX) and whichis connected to the cam follower plate 88 by means of a stud 126 thatengages a vertical slot 127 in the cam follower plate 88 (Figure XVII),and a driving pawl 128 which is attached to the rockable plate 124.Horizontal reciprocation of the cam follower plate 88 rocks the plate124 about the axis of the shaft 125. Clockwise rocking of the plate 124,as viewed in Figure XVII, causes the driving pawl 128 to turn a ratchetwheel 129 clockwise, the wheel 129 being

